The technology disclosed relates to systems and methods for testing adaptive antennas via a multi-probe anechoic chamber.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also correspond to implementations of the claimed inventions.
Multiple-Input-Multiple-Output (MIMO) antenna techniques are a key factor in achieving the high data rates promised by next-generation wireless technologies such as LTE and LTE-Advanced. In addition to the challenges these new techniques impose on the design and execution phases of wireless products, MIMO adds several new wrinkles to RF testing. One area that experiences a renewed sense of importance with MIMO is the topic of Over-the-Air (OTA) device testing.
Under ideal conditions an M×N MIMO system (one using M transmitting antenna elements and N receiving antenna elements) can increase maximum data rates by a factor of min{M,N}times those available from a Single-Input Single-output (SISO) system operating in the same bandwidth. In other words, a 4×2 MIMO system can (under ideal conditions) double the data rates available in a SISO implementation, while a 4×4 MIMO system might quadruple those rates. However, the real-world environment is not only far from ideal, it is far from static.
Most traditional SISO device testing is performed with a conducted signal. Test equipment is literally cabled to the transceiver of the device under test (DUT) by means of a temporary antenna connector, which effectively bypasses the device antennas. Supplementary SISO OTA tests are run in an anechoic chamber to characterize the antenna performance. These tests use two figures of merit to quantify antenna performance: Total Radiated Power (TRP) and Total Receiver Sensitivity (TRS, also known as Total Isotropic Sensitivity [TIS] by the CTIA). However, the results of OTA testing have been considered of secondary importance compared to conducted testing results.
One discussion of LTE testing from Agilent is by Rumney, “3GPP LTE Standards Update: Release 11, 12 and Beyond”, (uploaded to SlideShare Feb. 10, 2013) accessed at <http://www.slideshare.net/zahidtg/3gpp-lte-standards-update-release-11-12-and-beyond>.
An opportunity arises to provide new and improved systems and methods for testing adaptive antennas via a multi-probe anechoic chamber.